Ordnance Survey
Ordnance Survey, the UK’s mapping agency, is a partner on our project to explore new techniques to build 3D maps of towns and cities. We explain how their expanded abilities to provide mapping data helps our project.
Our team at the University of Glasgow researches cutting-edge approaches to utilising geospatial data. With modern big data, often the data that you are missing is as important as the data you have. For example, we’re using missing GPS signals to build 3D maps of cities.
Background
Photo: ©GSA, ©European GNSS Agency.
Modern phones use GPS signals to position themselves, receiving signals from many orbiting satellites. Only a few satellites are used to calculate your position, with the additional satellites needed to provide redundancy as their signals can be easily blocked. These blockages are caused by obstacles such as buildings. By analysing the patterns of blockages from many phones, we are able to generate 3D maps using only the data that your phone was already collecting. These 3D maps are useful for many things, including helping your phone estimate location with more accuracy.
We hope this approach can replace and/or complement current methods of building 3D maps which use LIDAR or aerial photos, as the cost of these approaches can be significant when repeated often enough to keep maps up to date.
We’re developing different algorithms to see how they perform, and OS data is invaluable in the process. The performance of algorithms can be improved by starting with an accurate 2D map, and OS MasterMap is the definitive vector map of Great Britain which we can access under licence for academic research through EDINA’s Digimap service. Of particular use to us is OS MasterMap’s building height attribute dataset. We use it as a benchmark to measure the relative accuracy of our algorithm results.
